Friedrich hofmann



(No Model.) 2 Sheets-Sheet 1.

F. HOFMANN.

DROP BOX CHANGING MECHANISM FOR POWER LOOMS. No. 500,768. Patented July4, 1893.

2 Sheets-Sheet 2.

(No Model.)

P. HOPMANN. DROP BOX CHANGING MECHANISM FOR POWER LOOMS. No. 500,768.

Patented July 4, 1-893.

UNITED STATES PATENT OFFICE.

FRIEDRICH HOFMANN, OF BARACCONNE, NEAR TURIN, ITALY, ASSIGNOR TO THEMASOI-IINENFABRIK RI ITI, FORMERLY KASPER I-IONEGGER, OF RUTI, CANTON OFZURICH, SWITZERLAND.

DROP-BOX-CHANGING MECHANISM FOR POWER-LOOMS.

SPECIFICATION forming part of Letters Patent No. 500,768, dated July 4,1893.

Application filed December 31, 1892.

To all whom it may concern:

Be it known that I, FRIEDRICH HOFMANN, a subject of the King of Italy,residing at Baracconne, near Turin, Italy, have invented certain new anduseful Improvements in Drop- Box-Ohanging Mechanism for Power-Looms, ofwhich the following is a specification.

This invention relates to improved drop shuttle box, changing mechanismfor power to looms and has for its object to insure the bringing of theshuttle boxes to their proper positions without shock, even when workingat a high speed.

Reference is to be had to the accompanying drawings, forming part ofthis specification,

wherein- Figure 1 is a sectional elevation showing the improvedmechanism. Fig. 2 is a perspective View of a part thereof. Figs. 3, 4t,5 and 6 are diagrams illustrating its operation. Figs. 7,

8, 9 and 10, show the four pattern cards corresponding to the fourpattern cards corresponding to the four positions of the mechanism.

The same letters of reference denote like parts in all the figures.

The mechanism receives its motion from the shaft a which by a cam coscillates the lever 17 to which is attached the rod 01 carrying the 0griif e which is thereby raised at each revolution of shaft a. Aneccentric f also fixed on shaft a imparts through the medium ofconnecting rod 9 and lever 72. the necessary horizontal oscillations tothe pattern card cylinder 5 i for the purpose of rotating the cylinder,changing the pattern cards, and moving the cylinder toward and away fromthe needle box lowhich contains four spring needles Z, each needle beingin connection with one of the 0 lifting hooks m, m m m These hooks m, mm m, are actuated in the usual way by the pattern cards acting throughthe needles, those of the hooks to whose needles perforations in thepattern cards coincide remaining in position to be engaged by the griff6 while the remainder of the hooks are forced back so as not to beengaged thereby. The hooks m to m are arranged behind one another asshown in Fig. 1 and work at the upper part through the needle box and atthe lower part Serial No. 456 910. (No model.)

in the guide n. m and m constitute one pair and m andm another pair ofhooks, the two hooks of each pair being connected by chains, bands orcords with and acting oppositely on a chain drum of which there are twop'p corresponding respectively to the two pairs of hooks. To each of thechain drums is attached an eccentric q or g each drum and its respectiveeccentric being rotatable independently of the other upon a stationaryshaft 0 and each chain drum has formed upon it two notched projectionsM00 each in the plane of the corresponding hook rod. At every ascent ofthe one or other hook of a pair, the eccentric q or (1 connected withthe drum thereby actuated is rotated through a semicircle so as to bebrought either from its lowest to its highest position or vice versa,according to which hook of the pair is actuated. The two eccentrics qand g are connected by links 1" r to the drop box lever s, the link 7''being connected to the middle of the lever at t and the link 7' with theend 25 of the lever, the connection in both cases being made by aspherical joint and the socket of the joint 25 being guided intransverse vertical slots u, in a guide bracket having a longitudinalvertical slot in which the lever s is guided whereby both lateral andlongitudinal motion of said lever are pre Vented. The standard w jointedto the end 3 of the lever s carries the drop box U which is raised andlowered to four different positions by the eccentrics q and g beingbrought to the various relative positions shown diagrammatically inFigs. 3, 4, 5 and 6, the eccentrics in their various positions acting onthe lever s and bringing it to the various heights and inclinationsshown. For instance the position of the eccentrics and lever in Fig. 3is produced by raising the hooks m and m and that shown in Fig. 4 byraising hooks m and m while those shown in Figs. 5 and 6 are produced byraising wires m m and m m respectively, the operation of the hooks beingdetermined as before stated by the perfora- 95 tions of the patterncards shown in Figs. 7, 8,

9 and 10. From these figures it will be seen that for each position ofthe shuttle box the simultaneous raising of one hook of each pair isrequisite. If the same hook be raised twice, mo

in succession, it will not cause the drum in connection with it torotate the second time but will only uselessly pull its chain.

The height of the shuttle box is accurately determined by the engagementwith the chain drums of the hook rods which are not raised. For thispurpose the lower ends of the hook rods are beveled and those which arenot raised by the griif, ride upon the corresponding cam-likeprojections 0n the chain drums and each drops into the notch or m whichis presented to it, when the other hook of the pair has been raised tosuch a height as to cause the eccentric attached to that drum to performa half-turn. The weight of the shuttle box is counterbalanced by aspiral spring y, Fig. 1, connected to the lever s by a chain passingover and engaging with an eccentric pulley mounted on the guide bracketof the lever s, the eccentricity of the pulley compen sating for thevariable height of the lever 8.

Having now particularly described and ascertained the nature of the saidinvention and in what manner the same is to be performed, I clairn 1. Incombination, the shuttle box with its support 10, the lever 8 connectedto said support at oneend, the independent shafts p, 10 the twoeccentrics on said shafts arranged to have independent action, theeccentric rod 1" leading from one of said eccentrics to one end of thelever and the rod r leading from the other eccentric to the middle partof the lever, the pair of lifter hooks m ,m the chains connecting saidrods to opposite sides of the shaft 10'', the second pair of rods m "mwith their chains connecting them in like manner to opposite sides ofthe shaft p and the means for operating the lifter hooks, substantiallyas described.

2. In combination, the shuttle box and its support, the lever s, the twoshafts pflp havin g eccentricsand drums thereon with notchedprojections, the eccentric rods connected to the lever s, the two pairsof lifter books, the chains connecting them to opposite sides of thechain drums, said lifter hooks being arranged when in their lowestposition to eng ge the notched projections of the drums and act asstopsand the means for operating the lifter hooks, substantially asdescribed.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

FRIEDRICH HO FMANN.

